146 PRINCIPLES OF ANIMAL NUTRITION. 
and fat given on p. 150 with those upon the same ration of meat 
without the fat, as in the table below: 
Number Food per Day. Gain or Loss by Body. 
of 
E i- A 
ments | Bens | cea. | NG | Sime” 
Proteids alone ........... 6 500 see —3.4 —49.1 
“and fat . oes 1 500 100 +0.3 +27.1 
a oro 5 500 200 —0.6 +67.3 
CARBOHYDRATES. — The more soluble hexose carbohydrates 
when given to a fasting animal serve, like the fats, as a source of 
energy for the organism in place of the body fat which would other- 
wise be oxidized. 
The following is a summary of the average results obtained by 
Pettenkofer & Voit * by feeding starch with a small amount of 
fat, the fasting metabolism being the same as that just given on 
p. 144. The averages are computed as before from Atwater & 
Langworthy’s digest (loc. cit.): 
Number Food per Day. Gain or Loss by Body. 
of 
Experi- 5 
Starch, Fat, Nit ' Carbon, 
mens: Gena: Gums: Gre. Grms. 
Piisting’ Soi caasece dan 5 aan ee ee 
1 450 16.9 —7.20 |.+19.40 
Starch: seccacssaviensedes 1 597 21.2 —9.40 | —28.50 
3 700 20.2 —6.20 | +61.30 
The fasting metabolism in this case represents a series of experi- 
ments antedating by a year or two that upon starch. In only one 
case were the respiratory products of the fasting animal determined 
during the latter series. That determination immediately fol- 
lowed a day on which a large amount of starch was consumed, 
and the results are believed by the authors to be affected thereby. 
No very strict comparison is therefore possible, but the general 
effect of the starch in diminishing the loss of body fat is evident. 
* Zeit. f. Biol., 9, 485. 
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